The present invention relates to sprinkler systems and pertains particularly to pop-up sprinkler systems.
Sprinkler units which retract into a housing in the ground when not in use, and which pop-up or extend from a housing in the ground when water pressure is supplied thereto, are widely used in both residential and commercial applications. The present pop-up type sprinkler units begin to operate as soon as water pressure is supplied thereto and the unit begins its rise from the housing. This operation of the unit before it clears the ground surface results in erosion of soil around the unit causing a large hole or cavity in the ground.
This operation may be tolerated for some situations, but is not satisfactory for most applications. For example, such units clearly cannot be used on putting greens of golf courses. Presently, putting greens of golf courses are watered by sprinkler units located off the green or by portable units that are moved onto and off the green as needed. These two approaches have a number of drawbacks, including labor, lack of adequate coverage and potential damage to the green.
It is, therefore, desirable that an improved pop-up sprinkler be available that can be utilized on putting greens.